# SPDX-License-Identifier: GPL-3.0-or-later

# Haketilo proxy data and configuration (update of dependency tree in the db).
#
# This file is part of Hydrilla&Haketilo.
#
# Copyright (C) 2022 Wojtek Kosior
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.
#
#
# I, Wojtek Kosior, thereby promise not to sue for violation of this
# file's license. Although I request that you do not make use this code
# in a proprietary program, I am not going to enforce this in court.

"""
....
"""

# Enable using with Python 3.7.
from __future__ import annotations

import sqlite3
import typing as t

from .... import item_infos
from ... import simple_dependency_satisfying as sds
from .. import base
from .pull_missing_files import pull_missing_files, FileResolver, \
    DummyFileResolver


AnyInfoVar = t.TypeVar(
    'AnyInfoVar',
    item_infos.ResourceInfo,
    item_infos.MappingInfo
)

def _get_infos_of_type(cursor: sqlite3.Cursor, info_type: t.Type[AnyInfoVar],) \
    -> t.Mapping[int, AnyInfoVar]:
    cursor.execute(
        '''
        SELECT
                ive.item_version_id,
                ive.definition,
                ive.repo,
                ive.repo_iteration
        FROM
                     item_versions_extra AS ive
                JOIN items               AS i USING (item_id)
        WHERE
                i.type = ?;
        ''',
        (info_type.type_name[0].upper(),)
    )

    result: dict[int, AnyInfoVar] = {}

    for item_version_id, definition, repo_name, repo_iteration \
        in cursor.fetchall():
        info = info_type.load(definition, repo_name, repo_iteration)
        result[item_version_id] = info

    return result

def _get_current_required_state(
        cursor:                     sqlite3.Cursor,
        unlocked_required_mappings: t.Sequence[int]
) -> list[sds.MappingRequirement]:
    # For mappings explicitly enabled by the user (+ all mappings they
    # recursively depend on) let's make sure that their exact same versions will
    # be enabled after the change. Make exception for mappings specified by the
    # caller.
    with base.temporary_ids_table(
            cursor     = cursor,
            ids        = unlocked_required_mappings,
            table_name = '__unlocked_ids'
    ):
        cursor.execute(
            '''
            SELECT
                    definition, repo, repo_iteration
            FROM
                    item_versions_extra
            WHERE
                    item_id NOT IN __unlocked_ids AND active = 'R';
            ''',
        )

        rows = cursor.fetchall()

    requirements: list[sds.MappingRequirement] = []

    for definition, repo, iteration in rows:
        info = item_infos.MappingInfo.load(definition, repo, iteration)
        req = sds.MappingVersionRequirement(info.identifier, info)
        requirements.append(req)

    return requirements

def _mark_version_installed(cursor: sqlite3.Cursor, version_id: int) -> None:
    cursor.execute(
        '''
        UPDATE
                item_versions
        SET
                installed = 'I'
        WHERE
                item_version_id = ?;
        ''',
        (version_id,)
    )

def _recompute_dependencies_no_state_update_no_pull_files(
        cursor:                     sqlite3.Cursor,
        unlocked_required_mappings: base.NoLockArg = [],
) -> None:
    cursor.execute('DELETE FROM payloads;')

    ids_to_resources = _get_infos_of_type(cursor, item_infos.ResourceInfo)
    ids_to_mappings  = _get_infos_of_type(cursor, item_infos.MappingInfo)

    resources_to_ids = dict((info, id) for id, info in ids_to_resources.items())
    mappings_to_ids  = dict((info, id) for id, info in ids_to_mappings.items())

    if unlocked_required_mappings == 'all_mappings_unlocked':
        requirements = []
    else:
        requirements = _get_current_required_state(
            cursor                     = cursor,
            unlocked_required_mappings = unlocked_required_mappings
        )

    cursor.execute(
        '''
        SELECT
                i.identifier
        FROM
                     mapping_statuses AS ms
                JOIN items            AS i  USING(item_id)
        WHERE
                ms.enabled = 'E' AND ms.frozen = 'N';
        '''
    )

    for mapping_identifier, in cursor.fetchall():
        requirements.append(sds.MappingRequirement(mapping_identifier))

    cursor.execute(
        '''
        SELECT
                active_version_id, frozen
        FROM
                mapping_statuses
        WHERE
                enabled = 'E' AND frozen IN ('R', 'E');
        '''
    )

    for active_version_id, frozen in cursor.fetchall():
        info = ids_to_mappings[active_version_id]

        requirement: sds.MappingRequirement

        if frozen == 'R':
            requirement = sds.MappingRepoRequirement(info.identifier, info.repo)
        else:
            requirement = sds.MappingVersionRequirement(info.identifier, info)

        requirements.append(requirement)

    mapping_choices = sds.compute_payloads(
        ids_to_resources.values(),
        ids_to_mappings.values(),
        requirements
    )

    cursor.execute(
        '''
        UPDATE
                mapping_statuses
        SET
                active_version_id = NULL
        WHERE
                enabled != 'E';
        '''
    )

    cursor.execute("UPDATE item_versions SET active = 'N';")

    cursor.execute('DELETE FROM payloads;')

    for choice in mapping_choices.values():
        mapping_ver_id = mappings_to_ids[choice.info]

        if choice.required:
            _mark_version_installed(cursor, mapping_ver_id)

        cursor.execute(
            '''
            SELECT
                    item_id
            FROM
                    item_versions
            WHERE
                    item_version_id = ?;
            ''',
            (mapping_ver_id,)
        )

        (mapping_item_id,), = cursor.fetchall()

        cursor.execute(
            '''
            UPDATE
                    mapping_statuses
            SET
                    active_version_id = ?
            WHERE
                    item_id = ?;
            ''',
            (mapping_ver_id, mapping_item_id)
        )

        cursor.execute(
            '''
            UPDATE
                    item_versions
            SET
                    active = ?
            WHERE
                    item_version_id = ?;
            ''',
            (mapping_ver_id, 'R' if choice.required else 'A')
        )

        for num, (pattern, payload) in enumerate(choice.payloads.items()):
            cursor.execute(
                '''
                INSERT INTO payloads(
                        mapping_item_id,
                        pattern,
                        eval_allowed,
                        cors_bypass_allowed
                )
                VALUES (?, ?, ?, ?);
                ''',
                (
                    mapping_ver_id,
                    pattern.orig_url,
                    payload.allows_eval,
                    payload.allows_cors_bypass
                )
            )

            cursor.execute(
                '''
                SELECT
                        payload_id
                FROM
                        payloads
                WHERE
                        mapping_item_id = ? AND pattern = ?;
                ''',
                (mapping_ver_id, pattern.orig_url)
            )

            (payload_id,), = cursor.fetchall()

            for res_num, resource_info in enumerate(payload.resources):
                resource_ver_id = resources_to_ids[resource_info]

                if choice.required:
                    _mark_version_installed(cursor, resource_ver_id)

                cursor.execute(
                    '''
                    INSERT INTO resolved_depended_resources(
                            payload_id,
                            resource_item_id,
                            idx
                    )
                    VALUES(?, ?, ?);
                    ''',
                    (payload_id, resource_ver_id, res_num)
                )

                new_status = 'R' if choice.required else 'A'

                cursor.execute(
                    '''
                    UPDATE
                            item_versions
                    SET
                            active = (
                                    CASE
                                    WHEN active = 'R' OR ? = 'R' THEN 'R'
                                    WHEN active = 'A' OR ? = 'A' THEN 'A'
                                    ELSE 'N'
                                    END
                            )
                    WHERE
                            item_version_id = ?;
                    ''',
                    (new_status, new_status, resource_ver_id)
                )


def _recompute_dependencies_no_state_update(
        cursor:                     sqlite3.Cursor,
        unlocked_required_mappings: base.NoLockArg = [],
        semirepo_file_resolver:     FileResolver   = DummyFileResolver()
) -> None:
    _recompute_dependencies_no_state_update_no_pull_files(
        cursor                     = cursor,
        unlocked_required_mappings = unlocked_required_mappings
    )

    pull_missing_files(cursor, semirepo_file_resolver)